Mortality in the first 5 years of life: a comparison among Italians and immigrants in the cohorts of the Italian Network of Longitudinal Metropolitan Studies

BACKGROUND: the considerable number of women in child-bearing age in the most recent migration flows has made maternal and child health of the foreign population a priority in most host Countries. Epidemiological studies comparing perinatal outcomes of children of immigrants in industrialized Countries with those of the native population have shown conflicting results. OBJECTIVES: to compare neonatal and post-neonatal mortality and mortality in 1-4-year-old children born to Italian mothers with that of children born to immigrant mothers. Turin, Reggio Emilia, Bologna, and Modena participated in this analysis of the Italian network of Metropolitan Longitudinal Studies (IN-LiMeS). METHODS: all children aged 0-4 years residing in Turin, Reggio Emilia, Bologna or Modena for at least one day between 01.01.2001 and 31.12.2012 (open cohort) were enrolled. The Municipal Registry archive was linked with the Italian National Registry of Causes of Death. Follow-up ceased either at death, emigration, or at 5th birthday. In the analysis of neonatal and post-neonatal mortality, only children born and registered in Italy were included in the study; follow-up concluded after 28 days for neonatal mortality and after one year for post-neonatal mortality (cohort of births). Children whose mother was a citizen of a Country with high migration were defined as immigrant. Neonatal, post-neonatal and 1-4-year-old children mortality rates by citizenship (immigrants vs Italians), by macroarea of citizenship, and by length of stay were compared using Odds Ratio (OR) calculated with logistic regression or Mortality Rate Ratio (MRR) calculated with Poisson regression only for 1-4-year-old children mortality rates, adjusting for child's gender, mother's age, mother's education level, calendar year, and city (pooled analysis). RESULTS: 238,753 children (20% with immigrant mother) were enrolled in the study. There were 402 deaths, 50% of which in the first 28 days of life. Immigrants had a neonatal and post-neonatal mortality risk about 1.5 times that of Italians, even after correcting for socioeconomic variables (neonatal: OR 1.71; 95%CI 1.22-2.39 - post-neonatal: OR 1.63; 95%CI 1.03-2.57). The difference disappeared in more recent years (2007-2013). A difference between Italians and immigrants was also observed for mortality in children aged 1-4 years, though less marked (OR 1.24; 95%CI 0.73-2.11), which remained constant over time. Excesses concerned particularly immigrants from North Africa and from sub-Saharan Africa as well as those residing in Italy for >5 years. CONCLUSIONS: this study highlights an excess in mortality for immigrants under the age of one, in particular those whose mothers are from Africa and/or have been living in Italy for more than 5 years. This excess mortality diminished over time.